The invention is directed to a process for automatically controlling the detoxification of waste waters containing nitrite ions, in which the nitrite ions are oxidized in the weakly acid pH range by means of hydrogen peroxide to form nitrate ions.
It has long been known that nitrite ions can be oxidized in the weakly acid pH range to nitrate ions by means of hydrogen peroxide. Although hydrogen peroxide represents a particularly environmentally favorable oxidizing agent, its use in practice failed in the detoxification of nitrite ions in waste waters of unknown or changing concentration because there existed no measuring technology for the oxidation reaction known in itself and consequently the reaction was not automatically controllable.